Figure 1. Lateral view of crayfish indicating number and position of cervical spines. Modified from Hobbs (1981).

2a. Claws with three or more tubercles along mesial margin of the palm; spine extending beyond margin of uropod(Fig. 2A)................................................................Cambarus acanthura2b. Claws with two rows of tubercles along mesial margin of the palm; spine does not extend beyond margin of uropod (Fig. 2B)...............................................................................go to 3

3a. Single well-developed cervical spine present.....................go to 43b. No cervical spine, at most cervical tubercle......................go to 6

4a. Antenna white in live individuals.......................Cambarus englishi4b. Antenna pinkish or brownish...........................................go to 5

5a. Claws olive to greenish; rostral margins and tubercles on palm near connection of moveable finger red.........................Cambarus halli5b. Claws brownish, no red tubercles present and no red on rostral margins................................................Cambarus latimanus, in part

6a. Areola usually more than 9 times as long as broad (Fig. 3A); rostrum typically somewhat blunt; some populations with distinct abdominal stripes...................................................Cambarus striatus6b. Areola usually less than 9 times as long as broad (Fig. 3B); rostrum tapering; some individuals with indistinct abdominal stripes.............................................................Cambarus latimanus